News on April 3, 2024, according to the announcement of the State Intellectual Property Office, Guangdong Zhongnan Iron and Steel Co., Ltd. applied for a project called "A manufacturing process for simplified annealed wire rods for grade 12.9 fasteners", publication number CN117802291A, application date for December 2023.
The patent abstract shows that the invention discloses a manufacturing process for simplified annealed wire rods for grade 12.9 fasteners. The manufacturing process flow is: steelmaking billet - billet heating - roughing and intermediate rolling mill rolling - pre-finishing rolling mill rolling - pre-finishing and post-cooling - finishing mill rolling - post-finishing cooling - reducing and sizing mill rolling After reduction and sizing, cooling, spinning and coiling, Stelmo air-cooling and line-controlled cooling, collecting wire rods for grade 12.9 fasteners. The tensile strength of medium and low carbon chromium needle alloy steel wire rods manufactured by this manufacturing process is less than 800MPa and the range is ≤100MPa, and the section shrinkage is ≥40%. There is no wire breakage problem during the direct drawing process of the wire rods, and the drawing process is reduced. One-time spheroidizing annealing reduces energy consumption.
